Regulatory Regions of the Homeotic Gene Proboscipedia Are Sensitive to Chromosomal Pairing
AUTOR(ES)
Kapoun, A. M.
RESUMO
We have identified regulatory regions of the homeotic gene proboscipedia that are capable of repressing a linked white minigene in a manner that is sensitive to chromosomal pairing. Normally, the eye color of transformants containing white in a P-element vector is affected by the number of copies of the transgene; homozygous flies have darker eyes than heterozygotes. However, we found that flies homozygous for select pb DNA-containing transgenes had lighter eyes than heterozygotes. Several pb DNA fragments are capable of causing this pairing sensitive (PS) negative regulation of white. Two fragments in the upstream DNA of pb, 0.58 and 0.98 kb, are PS; additionally, two PS sites are located in the second intron, including a 0.5-kb region and 49-bp sequence. This phenotype is not observed when two PS sites are located at different chromosomal insertion sites (in trans-heterozygous transgenic animals), indicating that the pb-DNA-mediated repression of white is dependent on the pairing or proximity of the PS regions. The observed phenomenon is similar to transvection in which certain alleles of a gene can complement each other, but only when homologous chromosomes are paired. Interestingly, the intronic PS regions contain positive regulatory sequences for pb, whereas the upstream PS sites contain pb negative regulatory elements.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1206641Documentos Relacionados
- Structural complexity and evolutionary conservation of the Drosophila homeotic gene proboscipedia.
- Ectopic Expression of the Drosophila Homeotic Gene Proboscipedia under Antennapedia P1 Control Causes Dominant Thoracic Defects
- Levels of homeotic protein function can determine developmental identity: evidence from low-level expression of the Drosophila homeotic gene proboscipedia under Hsp70 control.
- Regulatory elements controlling expression of the Drosophila homeotic gene fork head.
- Unusual Properties of Regulatory DNA from the Drosophila Engrailed Gene: Three ``pairing-Sensitive'' Sites within a 1.6-Kb Region